Today the college football world was semi-shocked to learn about the dismissal of Tyrann Mathieu from LSU due to undisclosed team violations. Mathieu has been no stranger to controversy—just last season he was suspended for his use of synthetic marijuana.

With an All-American talent now gone from the SEC, it is time to refresh the SEC defensive power rankings.

Does the dismissal make the Bayou Bengals drop from the top or will the overwhelming talent on the defense be enough to keep them on top? Alabama, Georgia and Florida now have a shot at taking the top spot.

No. 14: Kentucky Wildcats

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It will be another long season for the Wildcats this fall.

The Kentucky defense only returns five starters, and the Wildcats lose the top two tacklers with the departure of linebackers Danny Trevathan and Winston Guy. The Wildcats are also hurting in the secondary, with only one true starter returning and a new secondary coach coming on board this season.

The defensive line could be stout, but the Wildcats face a lot of dangerous ground attacks in the SEC—something that will not play out well for the Wildcats in 2012.

No. 13: Ole Miss Rebels

The Rebels are heading into the 2012 season with a new head coach and a number of changes coming with the new coaching staff.

Ole Miss returns a handful of experience on the defensive side of the ball in guys like Joel Kight and C.J. Johnson to name a few, but the Rebels are far from a game-changing defense.

As the Rebels transition this season into a new system and adapt to a new coaching staff, there will be growing pains. Unfortunately for the Rebels, there isn’t enough talent on the roster to pull out upsets or stifle the better offenses in the league.

No. 12: Missouri Tigers

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The Tigers are entering the first season of SEC play with their biggest defensive questions coming along the defensive line—and that will spell disaster in this league.

Missouri battled through injuries to Sheldon Richardson and Marvin Foster this spring and expect both to be completely back in the fold by the first game, but nagging injuries up front are always a concern. Behind those two in the middle, the Tigers only have one player with significant snaps—Jimmy Burge.

The Tigers have a solid linebacking corps, but they have serious issues at the safety position. Add an SEC schedule to the obvious depth concerns and the Tigers will face a lot of struggles early defensively.

No. 11: Texas A&M Aggies

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Texas A&M returns six starters to a defense that had spotty success a year ago, but the biggest question facing the Aggies is the changes that have come in scheme.

With Kevin Sumlin came the 4-3 base defense and defensive coordinator Mark Snyder. A number of the big outside linebackers that the Aggies played in the 3-4 have shifted to defensive ends, but the transition will not be easy.

The Aggies should be very good at linebacker, but the secondary loses three of four starters. The good news for the Aggies is that three of the returning secondary players are seniors, but stepping into the toughest league in the country is never fun when losing as much talent as the Aggies did.

Add to the losses a shift in scheme and a spread offense, and the Aggies are looking at a tough 2012 on the defensive side of the ball.

No. 10: Vanderbilt Commodores

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The Commodores saw huge improvement under James Franklin on both sides of the ball last season, but they walk into this season losing two of their top playmakers on defense with the departure of Chris Marve and Casey Hayward.

Rob Lohr and Colt Nichter are returning players on the defensive line that had huge campaigns last season. They will be the leaders and anchors of this season's defense.

Losing Chris Marve in the middle of the linebacker corps will be a huge blow for the Commodores in 2012. Vanderbilt has shifted outside linebacker Chase Garnham to the middle, but he only has six games of experience to his name—that is not an ideal solution to replace a three-time All-SEC linebacker.

In the secondary, the Commodores lose Casey Hayward and Sean Richardson with no one on roster that possesses the same game-changing abilities. Vanderbilt will be ok, but they will struggle early as they settle players into new roles for the coming season.

No. 9: Tennessee Volunteers

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The Vols return nine starters on defense this season, but they have a new coaching staff and scheme that they are attempting to implement in the 2012 season.

The Volunteers have talent scattered throughout the defense, but nothing is pointing to break-neck success for Tennessee with the new scheme change and the departure of Malik Jackson along the defensive line.

The linebacker position looks very strong with returning starters A.J. Johnson, Curt Maggitt and Herman Lathers. Lathers is coming off of a season-ending injury from a year ago, but he has the passion and ability to be special for Tennessee.

The secondary should be strong, as it will be led by senior Prentiss Waggner, but will it be good enough to carry the Vols to victory? It doesn’t seem likely.

The biggest question for the Vols is how they will transition to the new defensive scheme. Right now it is too big of a question mark to land them higher on the list.

No. 8: Arkansas Razorbacks

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The Razorbacks are entering the John L. Smith era with a lot of talent along the defensive front, but it is a unit that lost stud Jake Bequette. The defensive line is still expected to be the strength of the unit with Byran Jones and Robert Thomas returning.

The Hogs have a few questions at linebacker but return four seniors that will contribute consistently in the second level of the defense. Tenarius Wright was moved this spring from defensive end to middle linebacker to help shore up the position and will likely earn a lot of time at linebacker.

In the secondary, the Hogs have scattered experience and will rely on Darius Winston and Tevin Mitchell to anchor the cornerback position. Depth is the biggest concern in the secondary, but that won’t hurt the Razorbacks too much this fall.

No. 7: Auburn Tigers

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Auburn returns nine starters from a mediocre defense in 2011, but there is a wealth of talent and depth at every position. The defensive line will be the most dominant unit for the Tigers, with Corey Lemonier and friends looking to wreak havoc on opposing backfields.

The linebacker corps returns two starters in Jake Holland and Daren Bates, but the remaining outside linebacker position has yet to be filled so far through fall camp.

In the secondary, the Tigers return all but one of their starters and more than enough depth to keep up with any passing offense in the conference. The biggest question is, how will the Tigers develop in the complex defensive scheme being implemented this offseason by new defensive coordinator Brian VanGorder?

At this point it appears the Tigers will be talented, but may struggle early adjusting to the new scheme. The jury remains out on the Tigers despite the high numbers of returning starters and experienced backups.

No. 6: Mississippi State Bulldogs

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The Bulldogs will field the most talented defense for Mississippi State in recent memory as they march into the 2012 season.

The defense returns seven starters with a host of talent coming at the linebacker position. Cameron Lawrence is the most well-known defender for the Bulldogs, as he racked up 123 total tackles in 2011—that’s beast mode, in case you were wondering.

Johnthan Banks and Corey Broomfield may be the best cornerback tandem in the country once the 2012 season finishes, but losing Charles Mitchell at safety will cause concern for State as they push through fall camp.

The defensive line lost junior Fletcher Cox to the NFL Draft which is a blow, but Josh Boyd appears to be ready to step up and fill the void left behind by the departure.

No. 5: South Carolina Gamecocks

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The Gamecocks lost big time contributors Melvin Ingram and Travian Robertson this past season, but they return two of the best defensive ends in the college game with Jadeveon Clowney and Devin Taylor prepping to destroy opposing quarterbacks this fall.

The Gamecocks also lost two key contributors at the linebacker position, but have five seniors to pull from to find replacements. Reginald Bowens is set to have a very good season, as he came out of spring receiving lofty reviews from first year defensive coordinator Lorenzo Ward.

The secondary is a key concern for the Gamecocks with the departure of three contributing corners—most notably Stephon Gilmore—but Akeem Auguste is poised to have a good senior season for South Carolina.

21-game starter D.J. Swearinger returns for his senior season at safety, and has proven to be very dangerous floating in the back third of the defense. Expect much of the same this season.

No. 4: LSU Tigers

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The LSU Tigers are down to five returning full time starters heading into the 2012 season after the dismissal of Tyrann Mathieu from the defense, but the talent that is left behind will not be too worried over the loss.

LSU returns one of the most talented and dangerous defensive lines in the country, headlined by Barkevious Mingo and Sam Montgomery. The two combined for 28.5 tackles for loss and 17 sacks in 2011.

Linebacker will be a bit of a concern for the Tigers but Kevin Minter and Tahj Jones will be big playmakers for the Tigers in 2012. Luke Muncie will need to step up this season at linebacker if the Tigers want to be as productive as possible from the position.

The Tigers lose Morris Claiborne and Brandon Taylor in the secondary and will need to replace that production immediately. To add to the problem is the loss of Tyrann Mathieu and his 14 career turnovers.

Tharold Simon will be the de facto leader at corner with the loss of Mathieu, but guys like Jalen Collins and Eric Reid will need to step into big roles this fall for the Tigers to be as dangerous as they could have been with Mathieu still in the fold.

No. 3: Alabama Crimson Tide

Reloading is the word that precedes this Alabama defense that lost a ton of talent from the 2011 season, but the lack of experience that will fill vital roles lands the Tide’s defense at No. 3.

The Tide will replace three defenders in the secondary, but returning senior Robert Lester and talented corner Dee Milliner will help ease the transition. The Tide also bring in a talented JUCO Deion Belue to help fill the void at corner, but the SEC is a different animal that what he has witnessed at the JUCO level.

Alabama’s biggest concern is the void left at the linebacker position—possibly the best unit that has taken the field in crimson and white roamed the sideline a year ago. Guys like Nico Johnson and C.J. Mosley return after playing in scenario type roles a year ago, but youth is abundant and experience is lacking at the other two linebacker positions.

Along the line, Jesse Williams will anchor the middle, and Ed Stinson, Quinton Dial and Damion Square will look to capture the edge as ends in the Alabama 3-4.

The Tide has a lot of talent that fills the defensive depth chart, but a lack of proven players will hurt a unit coming off of what could be argued as the best defensive performance ever by a team in college football in 2011.

No. 2: Florida Gators

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The Gators will undoubtedly struggle on offense this fall, but the saving grace for the Gators will be the 10 starters that return on defense.

Florida is stacked with defensive talent and it starts up front. Sharrif Floyd is one of the most versatile defensive linemen in the country, with his 6’3”, 305 pound frame and his ability to bounce around the inside and outside of the Gators line—he will play both defensive end and tackle, depending on the situation.

Ronald Powell is another big name for the Gators, but an injury to his ACL during the spring game may hamper his return early into the 2012 season.

At linebacker, Jonathan Bostic and Jelani Jenkins are two of the best in the country and will fly around the football wherever it happens to be. Bostic finished 2011 with 94 tackles, Jenkins had 75. Darrin Kitchens is a rising junior that saw action in all 13 games for the Gators last season and should be a name to watch as the season unfolds.

In the secondary, the Gators have both corners returning, with Marcus Roberson and Cody Riggs taking the field in 2012. At safety, Matt Elam and Josh Evans lead a very talented and deep position set—one that will be dangerous for opposing quarterbacks this coming fall.

No. 1: Georgia Bulldogs

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Jarvis Jones is the headliner for the Bulldogs defense this fall, coming off of a huge redshirt sophomore season in 2011. Jones led the SEC in sacks and was an All-American selection for his performance. Guys like Alec Ogletree and Amarlo Herrera are not far behind and will help solidify the linebacker position for the Bulldogs this fall.

John Jenkins and Kwame Geathers are two of the toughest interior linemen in the country for 2012, and they both will be playing in red and black this fall. Surrounding them at end will be Abry Jones and Garrison Smith—both proven show-stoppers from the end position.

Ray Drew and Cornelius Washington are tweener-type players that will see time at linebacker and defensive end, giving opposing offenses fits in 2012.

Branden Smith, Sanders Commings and Bacarri Rambo have all had run-ins with the law in the offseason, but all three will be a part of a talented secondary once they make it back to the field in the first few weeks of the season.

A move by Malcolm Mitchell from wide receiver to defensive back this spring will be a move to keep an eye on this fall, as his skill level rivals the best secondary players in the country. He could become a player that plays on both sides of the ball for the Bulldogs this fall.

Damian Swann and Corey Moore are names to follow early in the season with the suspensions of Commings and Rambo, but they aren’t playing because they aren’t talented. Both will be very good players for the Bulldogs this fall.